AAON RN SERIES Installation Operation & Maintenance

Also see for RN Series: Installation, operation & maintanance manual Installation operation & maintenance Installation operation & maintenance Installation operation & maintenance Installation operation & maintenance

Contents

AAON RN SERIES Installation Operation & Maintenance Manual pdf 69 page image

69Table 19 - Acceptable RefrigerationCircuit ValuesAir-Cooled Cond./ Air-Source Heat PumpSub-Cooling 8-15°F / 2-4°F (HP)*Sub-Coolingwith Hot GasReheat8-15°F /2-6°F (HP)*Superheat 8-15°FWater-Cooled Cond./Water Source HeatPumpSub-Cooling 4-8°FSuperheat 8-15°F*In cooling mode operationAdjusting Sub-cooling and SuperheatTemperaturesThe system is overcharged if the sub-coolingtemperature is too high and the evaporator isfully loaded (low loads on the evaporatorresult in increased sub-cooling) and theevaporator superheat is within thetemperature range as shown in the tableabove (high superheat results in increasedsub-cooling).Correct an overcharged system by reducingthe amount of refrigerant in the system tolower the sub-cooling.The system is undercharged if the superheatis too high and the sub-cooling is too lowCorrect an undercharged system by addingrefrigerant to the system to reduce superheatand raise sub-cooling.If the sub-cooling is correct and thesuperheat is too high, the TXV may needadjustment to correct the superheat.Thermal expansion valve must beadjusted to approximately 8-15°F ofsuction superheat. Failure to havesufficient superheat will damage thecompressor and void the warranty.CAUTIONDO NOT OVERCHARGE!Refrigerant overcharging leads toexcess refrigerant in the condensercoils resulting in elevated compressordischarge pressure.CAUTION